Although useful advances are being made in energy saving devices such as organic-based organic light emitting diodes (OLEDs) and organic photovoltaic devices (OPVs), further improvements are still needed in providing better processing and performance. For example, one promising type of material is conducting polymers including, for example, polythiophenes. However, problems can arise with doping, purity, solubility, and processing. In particular, it is important to have a very good control over the solubility of alternating layers of polymer (e.g., orthogonal or alternating solubility properties among adjacent layers). In particular, hole injection layers and hole transport layers can present difficult problems in view of competing demands and the need for very thin, but high quality, films.
A need exists for a good platform system to control properties of hole injection and transport layers such as solubility and electronic energy levels such as, for example, HOMO and LUMO so that the materials can be adapted for different applications and to function with different materials such as light emitting layers, photoactive layers, and electrodes. In particular, good solubility and intractability properties are important. The ability to formulate the system for a particular application and provide the required balance of properties are also important.
As production processes for these materials are scaled-up, there is also a growing need to improve the methods for making these materials. In particular, there is a need for methods to decrease yield losses of comonomers during their purification. Furthermore, there is a need for methods to allow copolymerization without use of highly reactive comonomers.